CN113973098A

CN113973098A - Method and device for sending domain name system request

Info

Publication number: CN113973098A
Application number: CN202010642999.5A
Authority: CN
Inventors: 姚琦; 宗在峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2022-01-25
Also published as: US20230164111A1; EP4171086A1; EP4171086A4; WO2022007657A1

Abstract

The application provides a sending method and a sending device for a domain name system request, relates to the technical field of communication, and can improve domain name system DNS resolution efficiency. The method comprises the following steps: the terminal device determines an address of a first DNS server corresponding to the first application. The terminal device determines a first address of the terminal device based on the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server. After that, the terminal apparatus transmits DNS request information. Wherein the DNS request information comprises an identity of the first application, an address of the first DNS server and a first address of the terminal device.

Description

Method and device for sending domain name system request

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method and an apparatus for sending a domain name system request.

Background

A Packet Data Unit (PDU) session (session) is accessed to a Data Network (DN) through a packet data unit session anchor (PSA) network element, so that a terminal device performs data transmission with an Application Server (AS) in the DN. The PSA network element is also communicatively coupled to a Domain Name System (DNS) server. For the PSA network element, the application server, and the DNS server deployed in the same data network, the DNS server receives DNS request information from the PSA network element, resolves a domain name in the DNS request information to obtain an Internet Protocol (IP) address of the application server, and then provides the IP address to the terminal device through the PSA network element, so that the terminal device realizes data transmission with the application server according to the IP address of the application server.

In a multi-homing (MH) scenario, there are multiple PSA network elements for one PDU session. The user plane paths leading to different PSA network elements branch at a Branch Point (BP) device. One PSA network element corresponds to one DNS server, and a different PSA network element corresponds to a different DNS server. In the MH scenario, the terminal device includes multiple addresses and corresponds to multiple PSA network elements. Wherein, one address of the terminal device corresponds to one PSA network element, and different addresses of the terminal device correspond to different PSA network elements.

In the MH scenario, for a piece of DNS request information, the source (source) address in the DNS request information is an address of the terminal device, and corresponds to a PSA network element, and the destination (destination) address in the DNS request information is an address of a DNS server. If there is no correspondence between the PSA network element corresponding to the source address and the DNS server corresponding to the destination address in one piece of DNS request information, that is, communication cannot be performed between the PSA network element corresponding to the source address and the DNS server corresponding to the destination address, a phenomenon of "DNS resolution failure" occurs, resulting in low DNS resolution efficiency.

Disclosure of Invention

The embodiment of the application provides a method and a device for sending a domain name system request, which can improve DNS (domain name system) resolution efficiency.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, an embodiment of the present application provides a method for sending a domain name system request, where an execution subject of the method may be a terminal device or a chip applied to the terminal device. The following description will be given taking as an example that the execution main body is a terminal device. The method comprises the following steps: the terminal device determines an address of a first domain name system, DNS, server corresponding to the first application. The terminal device determines a first address of the terminal device based on the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server. After that, the terminal apparatus transmits DNS request information. Wherein the DNS request information comprises an identity of the first application, an address of the first DNS server and a first address of the terminal device.

Since there is a correspondence between the address of the first DNS server and the first address of the terminal device, and the first address of the terminal device corresponds to one PSA network element, that is, communication is enabled between the first DNS server and the PSA network element corresponding to the first address of the terminal device. Because the DNS request information sent by the terminal device comprises the address of the first DNS server and the first address of the terminal device, the DNS request information can be transmitted to the first DNS server through the PSA network element corresponding to the terminal device, thereby improving the success rate of DNS analysis and reducing the phenomenon of 'DNS analysis failure' caused by 'no communication between the DNS server and the PSA network element' in the prior art.

In a possible design, the sending method for a domain name system request in the embodiment of the present application further includes: the terminal device receives an address of a first DNS server from a session management function, SMF, network element and an address of the terminal device corresponding to the address of the first DNS server. For example, "the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server" may be carried in a routing rule (routing rule) and transmitted to the terminal device. That is, the SMF network element can provide the terminal device with information of "the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server".

In one possible design, the determining, by the terminal device, an address of a first DNS server corresponding to the first application includes: the terminal device receives an identification of a first application from the SMF network element and an address of the DNS server corresponding to the identification of the first application. For example, "the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application" may be carried in a routing rule (routing rule), and transmitted to the terminal device. Then, the terminal device determines the address of the first DNS server from the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application.

In this way, when the SMF network element provides the terminal device with "the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application", the terminal device can determine the address of the first DNS server according to the information provided by the SMF network element.

In one possible design, the identification of the first application corresponds to a plurality of DNS servers. The terminal device determines the address of the first DNS server according to the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application, and the method comprises the following steps: the terminal device determines a first DNS server satisfying a preset policy from a plurality of DNS servers. Wherein the preset policy comprises at least one of: the priority of the first DNS server meets a priority condition among the priorities of the plurality of DNS servers; the distance between the first DNS server and the terminal device satisfies a separation distance condition.

In this way, in the case that the identifier of the first application corresponds to a plurality of DNS servers, the terminal device can determine one DNS server from the plurality of DNS servers as the first DNS server according to the preconfigured preset policy, and further determine the address of the first DNS server.

In a second aspect, an embodiment of the present application provides a method for sending a domain name system request, where an execution subject of the method may be a branch point BP device, or a chip applied in the BP device. The following description will be given taking an example in which the execution subject is a BP apparatus. The method comprises the following steps: the BP equipment receives domain name system DNS request information from a terminal device, and then updates at least one of a source address and a destination address in the DNS request information to obtain updated DNS request information. The source address in the updated DNS request information is the first address of the terminal device, and the destination address in the updated DNS request information is the address of the first DNS server. And the BP equipment sends the updated DNS request information to the PSA network element of the session anchor point of the first packet data unit according to the source address in the updated DNS request information. The first PSA network element corresponds to a first address of the terminal device, and a destination address in the updated DNS request information is used for the first PSA network element to send the updated DNS request information to the first DNS server, so that the first DNS server can analyze the updated DNS request information.

Since the source address in the updated DNS request information is the first address of the terminal device, the destination address in the updated DNS request information is the address of the first DNS server. The first PSA network element corresponding to the first address of the terminal device can communicate with the first DNS server, so that the updated DNS request information can be transmitted to the first DNS server through the first PSA network element, thereby improving the success rate of DNS analysis and reducing the phenomenon of DNS analysis failure caused by 'no communication between the DNS server and the PSA network element' in the prior art.

In one possible design, the BP device updates at least one of a source address and a destination address in the DNS request information, including: the BP equipment updates at least one of a source address and a destination address in the DNS request information according to the identification of the first application in the DNS request information, or the BP equipment updates the destination address in the DNS request information according to the source address in the DNS request information, or the BP equipment updates the source address in the DNS request information according to the destination address in the DNS request information.

That is, in the process of updating the DNS request information, the BP device can update at least one of the source address and the destination address in the DNS request information based on the identifier of the first application in the DNS request information, or the source address of the DNS request information, or the destination address of the DNS request information, so as to obtain the updated DNS request information.

In one possible design, the BP device updates at least one of a source address and a destination address in the DNS request information according to an identifier of the first application in the DNS request information, including: and the BP equipment determines the address of the first DNS server corresponding to the identifier of the first application, and then updates the destination address in the DNS request information into the address of the first DNS server. The BP equipment determines the first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server, and then the BP equipment takes the source address in the DNS request information as the first address of the terminal device.

In this way, the BP device may update the source address and the destination address in the DNS request information based on the identifier of the first application to obtain updated DNS request information.

In one possible design, the BP device determining an address of a first DNS server corresponding to the identity of the first application includes: the BP equipment receives the identification of the first application from the SMF network element and the address of the DNS server corresponding to the identification of the first application, and then the BP equipment determines the address of the first DNS server according to the identification of the first application and the address of the DNS server corresponding to the identification of the first application.

Thus, when the SMF network element provides the "identifier of the first application and the address of the DNS server corresponding to the identifier of the first application" for the BP device, the BP device can determine the address of the first DNS server according to the information provided by the SMF network element.

In one possible design, the updating, by the BP device, the source address in the DNS request information according to the destination address in the DNS request information includes: if the destination address in the DNS request information is the address of the first DNS server, the BP device determines the first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server. After that, the BP device updates the source address in the DNS request information to the first address of the terminal apparatus.

That is, after receiving the DNS request information, the BP device replaces the source address in the DNS request information with reference to the destination address in the DNS request information, so as to ensure that the PSA network element corresponding to the source address in the updated DNS request information can communicate with the first DNS server.

In a possible design, the sending method for a domain name system request in the embodiment of the present application further includes: the BP device receives an address of a first DNS server from an SMF network element and an address of a terminal apparatus corresponding to the address of the first DNS server.

That is, the SMF network element can provide the BP apparatus with information of "the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server".

In one possible design, the BP device updates the destination address in the DNS request information according to the source address in the DNS request information, including: if the source address in the DNS request information is the first address of the terminal device, the BP device determines the address of the first DNS server according to the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device. And then, the BP equipment updates the destination address in the DNS request information into the address of the first DNS server.

That is, after the BP device receives the DNS request information, the destination address in the DNS request information is replaced with reference to the source address in the DNS request information, so as to ensure that communication can be performed between the PSA network element corresponding to the source address in the updated DNS request information and the first DNS server.

In a possible design, the sending method for a domain name system request in the embodiment of the present application further includes: the BP device receives a first address of a terminal device from an SMF network element and an address of a DNS server corresponding to the first address of the terminal device.

That is, the SMF network element can provide the BP apparatus with information of "the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device".

In a possible design, the sending method for a domain name system request in the embodiment of the present application further includes: the BP device receives response information for the DNS request information from the first PSA network element. And then, the BP equipment updates at least one of the source address and the destination address in the response information to obtain the updated response information. And the source address in the updated response information is the destination address of the DNS request information before updating, and the destination address in the updated response information is the source address of the DNS request information before updating. Then, the BP device transmits the updated response information to the terminal apparatus. The DNS request information comprises an identification of the first application, and the response information comprises an Internet Protocol (IP) address of an application server corresponding to the first application.

Here, the updated response information includes the IP address of the application server corresponding to the first application, the destination address of the DNS request information before update, and the source address of the DNS request information before update. After the terminal device sends the DNS request message, it needs to monitor a response message carrying a source address and a destination address of the DNS request message before updating. The BP device can replace at least one of the source address and the destination address in the response information to ensure that the terminal device can monitor the response message carrying the source address and the destination address of the DNS request information before updating.

In a third aspect, an embodiment of the present application provides a method for sending a domain name system request, where an execution subject of the method may be a branch point BP device, or a chip applied to the BP device. The following description will be given taking an example in which the execution subject is a BP apparatus. The method comprises the following steps: the BP equipment receives domain name system DNS request information from a terminal device, and then sends the DNS request information to a first packet data unit session anchor point PSA network element corresponding to a destination address according to the destination address in the DNS request information. The DNS request information is used for the first PSA network element to send the DNS request information to the first DNS server, so that the first DNS server can analyze the DNS request information.

Here, since the destination address of the DNS request information corresponds to the first PSA network element, the destination address of the DNS request information is the address of the first DNS server, and the first DNS server and the first PSA network element can communicate with each other, a phenomenon of "DNS resolution failure" caused by "communication failure between the DNS server and the PSA network element" in the prior art can be reduced, and a success rate of DNS resolution is improved.

In a fourth aspect, an execution subject of the method may be the first PSA network element, or a chip applied to the first PSA network element. The following description takes as an example that the execution subject is a first PSA network element. The method comprises the following steps: the first PSA network element sends DNS request information to a first Domain Name System (DNS) server. Wherein the DNS request information includes an address of the first DNS server and a second address of the terminal device corresponding to the second PSA network element. Thereafter, the first PSA network element receives response information for the DNS request information from the first DNS server. Then, the first PSA network element sends response information to the branch point BP device according to the forwarding rule information. Wherein the forwarding rule information is used for instructing the first PSA network element to send a data packet with a destination address as the second address to the BP equipment, and the data packet includes response information.

Here, the response information is response information for DNS request information. That is, in the process of feeding back the response information by the first DNS server, after the first PSA network element receives the response information from the first DNS server, even if the destination address of the response information is the second address of the terminal device, corresponding to the second PSA network element, the first PSA network element can transmit the response information to the BP device according to the forwarding rule information, so that the response information can be provided to the terminal device by the BP device.

In a possible design, the sending method for a domain name system request in the embodiment of the present application further includes: the first PSA network element receives forwarding rule information from a session management function, SMF, network element. That is, the SMF network element provides the forwarding rule information to the first PSA network element, so that the first PSA network element forwards the response information according to the forwarding rule information.

In one possible design, the first PSA network element receives response information for the DNS request information from the first DNS server, including: the first PSA network element receives response information for the DNS request information from the first DNS server through the tunnel between the first PSA network element and the first DNS server. The DNS request information comprises an identification of the first application, and the response information comprises an Internet Protocol (IP) address of an application server corresponding to the first application.

That is, the tunnel between the first PSA network element and the first DNS server can mask the destination address in the response message so that the response message can be transmitted from the first DNS server to the first PSA network element.

In a fifth aspect, an embodiment of the present application provides a device for sending a domain name system request, where the device for sending a domain name system request includes: means for performing the steps of any of the above aspects. The sending device of the domain name system request may be the terminal device in any one of the possible designs of the first aspect or the first aspect, or a chip that implements the function of the terminal device. The sending device of the domain name system request comprises modules, units or means (means) corresponding to the implementation of the method, and the modules, units or means can be implemented by hardware, software or hardware to execute corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a sixth aspect, an embodiment of the present application provides a device for sending a domain name system request, including a processor and an interface circuit, where the processor is configured to communicate with other devices through the interface circuit, and execute a sending method of a domain name system request provided in any one of the above aspects. The processor includes one or more. The sending device of the domain name system request may be the terminal device in any one of the possible designs of the first aspect or the first aspect, or a chip that implements the function of the terminal device.

In a seventh aspect, an embodiment of the present application provides a device for sending a domain name system request, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the sending device of the domain name system request to perform the method of any of the above aspects. The sending device of the domain name system request may be the terminal device in any one of the possible designs of the first aspect or the first aspect, or a chip that implements the function of the terminal device.

In an eighth aspect, an embodiment of the present application provides a device for sending a domain name system request, including: a processor; the processor is configured to be coupled to the memory, and after reading the instructions in the memory, perform the method according to any one of the above aspects. The sending device of the domain name system request may be the terminal device in any one of the possible designs of the first aspect or the first aspect, or a chip that implements the function of the terminal device.

In a ninth aspect, an embodiment of the present application provides a sending apparatus for a domain name system request, where the sending apparatus for a domain name system request includes: means for performing the steps of any of the above aspects. The sending device of the domain name system request may be a BP device in any one of the possible designs of the second aspect or the second aspect, or a chip that implements the function of the BP device; alternatively, the sending device of the domain name system request may be the BP device in any one of the possible designs of the third aspect or the third aspect, or a chip that implements the function of the BP device. The sending device of the domain name system request comprises modules, units or means (means) corresponding to the implementation of the method, and the modules, units or means can be implemented by hardware, software or hardware to execute corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a tenth aspect, an embodiment of the present application provides a device for sending a domain name system request, including a processor and an interface circuit, where the processor is configured to communicate with other devices through the interface circuit, and execute a sending method of a domain name system request provided in any one of the above aspects. The processor includes one or more. The sending device of the domain name system request may be a BP device in any one of the possible designs of the second aspect or the second aspect, or a chip that implements the function of the BP device; alternatively, the sending device of the domain name system request may be the BP device in any one of the possible designs of the third aspect or the third aspect, or a chip that implements the function of the BP device.

In an eleventh aspect, an embodiment of the present application provides an apparatus for sending a domain name system request, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the sending device of the domain name system request to perform the method of any of the above aspects. The sending device of the domain name system request may be a BP device in any one of the possible designs of the second aspect or the second aspect, or a chip that implements the function of the BP device; alternatively, the sending device of the domain name system request may be the BP device in any one of the possible designs of the third aspect or the third aspect, or a chip that implements the function of the BP device.

In a twelfth aspect, an embodiment of the present application provides a device for sending a domain name system request, including: a processor; the processor is configured to be coupled to the memory, and after reading the instructions in the memory, perform the method according to any one of the above aspects. The sending device of the domain name system request may be a BP device in any one of the possible designs of the second aspect or the second aspect, or a chip that implements the function of the BP device; alternatively, the sending device of the domain name system request may be the BP device in any one of the possible designs of the third aspect or the third aspect, or a chip that implements the function of the BP device.

In a thirteenth aspect, an embodiment of the present application provides a sending apparatus for a domain name system request, where the sending apparatus for a domain name system request includes: means for performing the steps of any of the above aspects. The sending device of the domain name system request may be the first PSA network element in any one of the possible designs of the fourth aspect or the fourth aspect, or a chip that implements the function of the first PSA network element. The sending device of the domain name system request comprises modules, units or means (means) corresponding to the implementation of the method, and the modules, units or means can be implemented by hardware, software or hardware to execute corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a fourteenth aspect, an embodiment of the present application provides a device for sending a domain name system request, including a processor and an interface circuit, where the processor is configured to communicate with other devices through the interface circuit, and execute a sending method of a domain name system request provided in any one of the above aspects. The processor includes one or more. The sending device of the domain name system request may be the first PSA network element in any one of the possible designs of the fourth aspect or the fourth aspect, or a chip that implements the function of the first PSA network element.

In a fifteenth aspect, an embodiment of the present application provides a device for sending a domain name system request, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the sending device of the domain name system request to perform the method of any of the above aspects. The sending device of the domain name system request may be the first PSA network element in any one of the possible designs of the fourth aspect or the fourth aspect, or a chip that implements the function of the first PSA network element.

In a sixteenth aspect, an embodiment of the present application provides an apparatus for sending a domain name system request, including: a processor; the processor is configured to be coupled to the memory, and after reading the instructions in the memory, perform the method according to any one of the above aspects. The sending device of the domain name system request may be the first PSA network element in any one of the possible designs of the fourth aspect or the fourth aspect, or a chip that implements the function of the first PSA network element.

In a seventeenth aspect, an embodiment of the present application provides a computer-readable storage medium, having stored therein instructions, which, when executed on a computer, enable the computer to perform the method for sending a domain name system request according to any one of the above aspects.

In an eighteenth aspect, embodiments of the present application provide a computer program product containing instructions that, when executed on a computer, enable the computer to perform the method for sending a domain name system request according to any one of the above aspects.

In a nineteenth aspect, embodiments of the present application provide circuitry that includes processing circuitry configured to perform the method for sending a domain name system request according to any one of the above aspects.

In a twentieth aspect, an embodiment of the present application provides a chip, where the chip includes a processor, the processor is coupled to a memory, and the memory stores program instructions, and when the program instructions stored in the memory are executed by the processor, the method for sending a domain name system request according to any one of the above aspects is implemented.

In a twenty-first aspect, an embodiment of the present application provides a system for sending a domain name system request, where the system for sending a domain name system request includes the terminal apparatus in any one of the above-mentioned first aspects, or includes the BP device in any one of the second aspects, or includes the BP device in any one of the third aspects and the first PSA network element in any one of the fourth aspects.

The technical effects brought by any design of the fifth aspect to the twenty-first aspect can refer to the beneficial effects in the corresponding methods provided above, and are not repeated herein.

Drawings

Fig. 1 is a schematic diagram of a network architecture according to an embodiment of the present application;

fig. 2 is a schematic diagram of another network architecture provided in an embodiment of the present application;

fig. 3 is a flowchart illustrating a method for sending a domain name system request according to an embodiment of the present application;

fig. 4 is a flowchart illustrating a method for sending a domain name system request according to an embodiment of the present application;

fig. 5 is a flowchart illustrating a method for sending a domain name system request according to another embodiment of the present application;

fig. 6 is a flowchart illustrating a further method for sending a domain name system request according to an embodiment of the present application;

fig. 7 is a flowchart illustrating a method for sending a domain name system request according to another embodiment of the present application;

fig. 8 is a flowchart illustrating a further method for sending a domain name system request according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of a device for sending a domain name system request according to an embodiment of the present application;

fig. 10 is a schematic structural diagram of a device for sending a domain name system request according to an embodiment of the present application.

Detailed Description

The terms "first" and "second" and the like in the description and drawings of the present application are used for distinguishing different objects or for distinguishing different processes for the same object, and are not used for describing a specific order of the objects. Furthermore, the terms "including" and "having," and any variations thereof, as referred to in the description of the present application, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements but may alternatively include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. In the embodiments of the present application, "a plurality" includes two or more. In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

First, technical terms referred to in the embodiments of the present application are introduced:

1. domain name resolution

The DNS is a distributed database on the internet as a mapping between domain names and Internet Protocol (IP) addresses, and can map domain names to IP addresses of application servers. Here, the process of mapping a domain name to an IP address of an application server is referred to as "domain name resolution".

A domain name, also called a web domain, is the name of a computer or group of computers on the internet that is composed of a string of names separated by dots, and is used to identify the electronic position or geographic location of the computer during data transmission. For example, the domain name may be www.123456.com.cn.

The domain name resolution equipment in the DNS is the DNS server. Here, the DNS server can resolve the domain name requested by the terminal device by the domain name resolution mechanism to obtain the IP address of the application server corresponding to the domain name. Alternatively, the number of DNS servers may be multiple and distributed in a hierarchical architecture. In the domain name resolution mechanism, the DNS sequentially passes through low-to-high hierarchical DNS servers to resolve the domain name until the IP address of the application server corresponding to the domain name is obtained. The domain name resolution mechanism is not described in detail in the embodiment of the present application.

Illustratively, the procedure for the terminal device to access the target domain name is as follows: after acquiring the target domain name, the terminal device sends DNS request information carrying the target domain name to the DNS server. Accordingly, the DNS server receives DNS request information from the terminal device. And then, the DNS server analyzes the IP address of the target application server corresponding to the target domain name, and carries the IP address of the target application server in response information and sends the response information to the terminal device. Correspondingly, the terminal device receives the response information from the DNS server, so that the terminal device obtains the IP address of the target application server and realizes data transmission with the target application server according to the IP address. Here, the "DNS request information" may also be described as a "request message", or a "domain name resolution request message". The "response message" may also be described as a "response message", or a "DNS reply (response)", or a "domain name resolution response message", corresponding to the DNS request information.

2. PDU session

A PDU session, which is a connection between a terminal device and a data network, is used to transfer data between the terminal device and the data network. The terminal device may connect to the same data network or different data networks through multiple PDU sessions.

3. MH mechanism

The end devices may be connected to the same data network through one or more PDU sessions served by different PSA network elements. Here, the PSA network element may be a User Plane Function (UPF) network element connected to a data network. The PSA may also be denoted as PDU session anchor point UPF. In the embodiments of the present application, "UPF as PSA" is exemplified. In the MH mechanism, one PDU session is accessed into the data network through multiple PSA network elements. The user plane path BP equipment leading to different PSA network elements branches. Here, the BP device may also be a UPF network element.

In the MH mechanism, the terminal device includes a plurality of addresses and corresponds to a plurality of PSA network elements. Wherein, one address of the terminal device corresponds to one PSA network element, and different addresses of the terminal device correspond to different PSA network elements.

In the process of accessing the target domain name by the terminal device, the terminal device sends DNS request information to the BP equipment. Accordingly, the BP device receives DNS request information from the terminal apparatus. The DNS request information comprises a source address and a destination address besides a target domain name. Wherein, the source address in the DNS request message is an address of the terminal device and corresponds to a PSA network element. The destination address in the DNS request message is an address of a DNS server. If there is no correspondence between the PSA network element corresponding to the source address and the DNS server corresponding to the destination address in one piece of DNS request information, that is, communication cannot be performed between the PSA network element corresponding to the source address and the DNS server corresponding to the destination address, a phenomenon of "DNS resolution failure" occurs, resulting in low DNS resolution efficiency.

In view of this, an embodiment of the present application provides a method for sending a domain name system request, and first, a system to which the method for sending a domain name system request in the embodiment of the present application is applied is described, where the system may be a communication system supporting a fifth-generation (5G) mobile communication technology, such as an NR access technology; alternatively, the system may also be a communication system supporting multiple radio technologies, such as a communication system supporting LTE technology and a New Radio (NR) access technology. In addition, the system may also be adapted for future oriented communication technologies.

Referring to fig. 1, a network architecture of a communication system supporting 5G mobile communication technology is described as an example. The network elements in the 5G network architecture include a terminal device, AN Access Network (AN) device, AN access and mobility management function (AMF) network element, a Session Management Function (SMF) network element, a PSA network element, a BP device, a Data Network (DN), and the like. Only two PSA network elements are shown in figure 1. Fig. 1 is a schematic diagram, and does not constitute a limitation on an applicable scenario of a sending method requested by a domain name system according to an embodiment of the present application.

A terminal apparatus, also called User Equipment (UE), terminal equipment, Mobile Station (MS), Mobile Terminal (MT), etc., is a device that provides voice/data connectivity to a user, for example, a handheld device or a vehicle-mounted device with a wireless connection function. The terminal device may specifically be: a mobile phone (mobile phone), a tablet computer, a notebook computer, a palm top computer, a Mobile Internet Device (MID), a wearable device, a Virtual Reality (VR) device, an Augmented Reality (AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote surgery (remote medical supply), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (smart security), a wireless terminal in city (smart city), a wireless terminal in smart home (smart home), a terminal device in a future 5G communication network or a communication network after 5G, and the like, which are not limited in this embodiment.

The access network device may also be a Radio Access Network (RAN) device, which is a device deployed in a radio access network to provide a radio communication function. Optionally, the RAN device according to the embodiments of the present application includes, for example and without limitation, macro base stations, micro base stations (also referred to as small stations), relays, Transmission Reception Points (TRPs), next generation network nodes (g Node bs, gnbs), evolved Node bs (ng-enbs) connected to a next generation core network, and RAN devices of non-third generation partnership project (3 GPP) systems, such as Wireless Local Area Network (WLAN) access devices.

The AMF network element has the functions of mobility management, registration management, connection management, lawful monitoring, Session Management (SM) information supporting transmission between the terminal device and the SMF, access authentication, access authorization and the like.

And the SMF network element has the functions of session management, roaming and the like. Among them, session management functions, such as session establishment, modification, and release. Roaming functions may include charging data collection, signaling to support authentication/authorization with external (external) data networks.

The PSA network element is a functional network element of the user plane, and is mainly responsible for connecting to an external network and processing user packets, such as forwarding, charging, and lawful interception. Optionally, the PSA network element may also receive data. Only two PSA network elements are shown in fig. 1, denoted PSA network element 1 and PSA network element 2, respectively.

And the BP equipment can receive the uplink data packet from the terminal device and distribute the uplink data packet to the PSA network element corresponding to the source address according to the source address of the uplink data packet. The BP device is also capable of receiving the downlink data packet from the PSA network element, aggregating the downlink data packet received from the PSA network element, and transmitting the aggregated downlink data packet to the terminal apparatus. Here, the BP device may also be implemented as a UPF network element.

The data network is a network for providing services for the terminal device, for example, some data networks provide an internet access function for the terminal device, and other data networks provide a short message function for the terminal device.

The terminal device communicates with the AMF network element through AN N1 interface, the AN equipment communicates with the AMF network element through AN N2 interface, the AN equipment communicates with the BP equipment through AN N3 interface, the BP equipment communicates with the SMF network element through AN N4 interface, the BP equipment communicates with the UPF network element through AN N9 interface, the UPF network element communicates with the SMF network element through AN N4 interface, the UPF network element accesses a data network through AN N6 interface, and the AMF network element communicates with the SMF network element through AN N11 interface. In fig. 1, the dotted line shows a path capable of control plane signaling interaction, and the solid line shows a path capable of user plane data interaction.

It should be noted that the data networks connected to different PSA network elements are located in different Data Centers (DC). Still taking the scenario shown in fig. 1 as an example, the distribution status of the data network will be described. Referring to fig. 2, the data network connected to the PSA network element 1 may be a central data network (central data network) or a central data center (central data center). In this case, PSA network element 1 may be referred to as the Central PSA, C-PSA for short. The data network connected to PSA network element 1 may also be a remote data network (remote data network) or a remote data center (remote data center). In this case, the PSA network element 1 may be denoted as remote PSA, abbreviated as R-PSA. The PSA network element 1 is also able to communicate with the DNS server in the data network described above. The data network to which PSA network element 2 is connected is located at a local DC or Edge Data Network (EDN). In this case, the PSA network element 2 may be denoted as Local PSA, abbreviated as L-PSA. Different L-PSA network elements may identify different numerical suffixes. For example, the first L-PSA network element may be designated L-PSA _1 and the second L-PSA network element may be designated L-PSA _ 2. The PSA network element 2 is also able to communicate with a DNS server in the local DC. There may be no IP connectivity between the PSA network elements and the DNS server located in different DCs, and no communication is possible. For example, the PSA network element 1 cannot communicate with a DNS server in the local DC. The PSA network element 2 cannot communicate with the DNS server in the central DC. When the terminal device is located with the PSA network element 2 so that the terminal device accesses the DN in the local DC, the SMF network element inserts this PSA network element 2 as a local PSA into the session path so that the terminal device can access the application in the local DN nearby. The BP equipment and the L-PSA network element can be separately deployed or jointly deployed. In the scenario shown in fig. 2, the function of the BP device and the function of the PSA network element 2 are implemented by the same network element, which may be the PSA network element 2.

Here, the local DC or edge data network may be implemented as a mobile/multi-access edge computing (MEC) node. Typically, an MEC node comprises an MEC platform and a data plane functional network element. Various application servers, DNS servers, and the like may be deployed on the MEC platform, which is not specifically limited in this embodiment of the present application. The MEC platform in the embodiment of the present application may also be referred to as an MEC system or other, which is not specifically limited in the embodiment of the present application. The data plane function network element may be implemented by a PSA network element. The application server refers to a carrier capable of providing a corresponding service. For example, the wechat application server may be a carrier capable of providing wechat services. The carrier may be a virtual device, such as a virtual machine or a container, or may be an entity device, which is not specifically limited in this embodiment of the present application.

The system and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation on the technical solution provided in the embodiment of the present application. As can be known to those skilled in the art, with the evolution of network architecture and the emergence of new service scenarios, the technical solution provided in the embodiments of the present application is also applicable to similar technical problems.

The following specifically explains a sending method for a domain name system request provided in the embodiment of the present application.

It should be noted that, in the following embodiments of the present application, the names of messages between network elements or the names of parameters in messages, etc. are only examples, and other names may also be used in specific implementations, which are described in a unified manner herein and will not be described again below.

The embodiment of the application provides a first method for sending a domain name system request, which is applied to a domain name resolution process. Referring to fig. 3, a method for sending a domain name system request according to an embodiment of the present application includes the following steps:

s301, the terminal device creates a PDU session.

Illustratively, the terminal device initiates a session creation request message to create a PDU session. The PDU session creation process is performed by a network device (e.g., SMF network element and UPF network element) and a terminal device. The detailed implementation process of the session creation flow can be referred to in the prior art, and is not described herein again.

The user plane path of the PDU session includes: a path from the RAN equipment to the BP equipment, and a path from the BP equipment to the PSA network element. Here, the number of PSA network elements is two or more. The PSA network element may be a PSA network element in the local DC, and may be a PSA network element in the central DC. Accordingly, the terminal apparatus is assigned a plurality of addresses. In an actual application process, the address allocated to the terminal device may be a specific address, such as an address of internet protocol version 4 (IPv 4), or may be an address prefix (prefix), such as an address prefix of internet protocol version 6 (IPv 6). One address of the terminal device corresponds to one PSA network element and different addresses of the terminal device correspond to different PSA network elements. The plurality of addresses of the terminal device may be assigned by the SMF network element or may be assigned by the PSA network element. In the case where the PSA network elements assign addresses to the terminal devices, one PSA network element assigns one address to the terminal device, and different PSA network elements assign different addresses to the terminal device. Illustratively, referring to table 1, table 1 shows the correspondence between the address of the terminal device and the PSA network element.

TABLE 1

Address of terminal device	PSA network element
		Address @0 of terminal device	C-PSA
Address @1 of terminal device	L-PSA_1
		…
Address @ n of terminal device	L-PSA_n

Referring to table 1, table 1 shows (n +1) addresses of the terminal device, respectively noted as: address of terminal device @0, address of terminal device @1, …, address of terminal device @ n. The number of PSA network elements is (n +1), which are respectively noted as: C-PSA, L-PSA _1, …, L-PSA _ n. In table 1, there is a correspondence between the addresses of the terminal devices located on the same row and the PSA network element. As shown in table 1, "address of terminal device @ 0" corresponds to "C-PSA" network element, "address of terminal device @ 1" corresponds to "L-PSA _ 1" network element, …, "address of terminal device @ n" corresponds to "L-PSA _ n" network element.

In addition, the PSA network element is able to serve or access a particular data network/data center. DNS servers may be deployed in these "data networks/data centers" for DNS resolution by DNS servers. The DNS server may also be deployed on the PSA network element, and the DNS server may also be deployed on the path between the PSA network element and the "data network/data center". The deployment position of the DNS server is not limited, and the PSA network element is ensured to be capable of sending the DNS request information to the corresponding DNS server after receiving the DNS request information. Thus, there is a correspondence between the DNS server and the "data network/data center", as well as a correspondence between the PSA and the "data network/data center". That is, for the PSA network element and the DNS server corresponding to the same "data network/data center", communication is enabled between the two, that is, a correspondence exists. For example, referring to table 2, table 2 shows the correspondence between the PSA network element and the DNS server, taking "address of DNS server" as an example. Here, the address of the DNS server may be identified by an IP address or a domain name or the like. Here, the addresses of at least two DNS servers are different. That is, the addresses of the DNS servers are not all the same. The addresses of different DNS servers may or may not be the same.

TABLE 2

Address of DNS server	PSA network element
		IP@0	C-PSA
IP@1	L-PSA_1
		…
IP@n	L-PSA_n

Referring to table 2, table 2 shows the addresses of (n +1) DNS servers, respectively noted: IP @0, IP @1, …, IP @ n. In the above, "IP @0, IP @1, …, and IP @ n" there may be the same address. The number of PSA network elements is (n +1), which are respectively noted as: C-PSA, L-PSA _1, …, L-PSA _ n. In table 2, there is a correspondence between DNS servers located in the same row and PSA network elements, as shown in table 2, for example, "IP @ 0" corresponds to a "C-PSA" network element, "IP @ 1" corresponds to an "L-PSA _ 1" network element, and …, "IP @ n" corresponds to an "L-PSA _ n" network element.

Note that table 1 shows "correspondence between the address of the terminal device and the PSA network element" only in the form of a "table". Table 2 shows "correspondence between PSA network elements and DNS servers" only in the form of "table". Tables 1 and 2 may be combined in the same table to present "the correspondence between the address of the terminal device and the PSA network element" and "the correspondence between the PSA network element and the DNS server", which is not limited in this embodiment of the present application.

S302, the terminal device determines the address of the first DNS server corresponding to the first application.

The first application may refer to a software product installed on the terminal device for accessing a service provided by the application server. These software products may also be referred to as application clients.

The "first DNS server corresponding to the first application" means that the application server corresponding to the first application is deployed in the data network corresponding to the first DNS server. The address of the first DNS server may be identified by an IP address or a domain name, etc.

Illustratively, the first application may be a wechat client on the terminal device. Correspondingly, the application server is a wechat application server and provides services for wechat clients on the terminal device. The first DNS server is a DNS server capable of resolving DNS request information including the WeChat application. Taking the scenario shown in fig. 2 as an example, if an application of "WeChat" is deployed on an application server in the central DC, and an application of "WeChat" is not deployed on an application server in the local DC, the first DNS server may be a DNS server in the central DC, and may be denoted as a "C-DNS" server. On the contrary, if the application server in the central DC does not deploy the application of "WeChat", and the application server in the local DC deploys the application of "WeChat", the first DNS server is a DNS server in the central DC, and may be referred to as an "L-DNS" server.

It should be noted that, since different data networks may have different applications deployed, application servers in the same data network are generally responsible for resolution by DNS servers corresponding to the data network. Therefore, there is a certain correspondence between different applications and different DNS servers. For example, referring to table 3-1, table 3-1 shows "correspondence between different applications and different DNS servers" by taking "identification of applications" and "address of DNS server" as an example. Here, the identification of the application may be a Fully Qualified Domain Name (FQDN). There is a one-to-one correspondence between the data network and the addresses of the DNS servers, so the "correspondence between different applications and different DNS servers" can also indicate which applications are deployed in the data network to which the DNS servers correspond.

TABLE 3-1

Identification of applications	Address of DNS server
		FQDN_1	IP@1
FQDN_1	IP@2
		FQDN_2	IP@1
FQDN_3	IP@3
		…	…
FQDN_n	IP@2

Referring to Table 3-1, Table 3-1 shows the identification of n applications, respectively noted: FQDN _1, FQDN _2, …, FQDN _ n. The number of DNS servers is at least two. The addresses of the three DNS servers are shown in table 3-1, respectively: IP @1, IP @2 and IP @ 3. In table 3-1, there is a correspondence between applications located on the same row and the DNS server. As shown in table 3-1, there is a correspondence between the application identified by "FQDN _ 1" and the DNS server having the address "IP @ 1", there is a correspondence between the application identified by "FQDN _ 1" and the DNS server having the address "IP @ 2", there is a correspondence between the application identified by "FQDN _ 2" and the DNS server having the address "IP @ 1", there is a correspondence between the application identified by "FQDN _ 3" and the DNS server having the address "IP @ 3", and there is a correspondence between the application identified by "FQDN _ n" and the DNS server having the address "IP @ 2". The terminal device may pre-configure information of "correspondence between application and DNS server", or may send information of "correspondence between application and DNS server" to the terminal device by the SMF network element, the PCF network element, or another network element. For example, in the process of inserting the BP device into the user plane path of the PDU session, the SMF network element or the PCF network element carries the information of the "correspondence between the application and the DNS server" when sending a User Routing Selection Policy (URSP) for the terminal device.

Here, there are various ways of determining, by the terminal device, the address of the first DNS server corresponding to the first application, and the method may be, for example and without limitation, the processing procedure shown in fig. 4:

s3021, the SMF network element transmits the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application to the terminal apparatus. Accordingly, the terminal device receives an identification of the first application from the SMF network element and an address of the DNS server corresponding to the identification of the first application.

For example, the "identifier of the first application and the address of the DNS server corresponding to the identifier of the first application" may be presented in a table form, or may be presented in other forms, which is not limited in this embodiment of the application. Taking Table 3-1 as an example, the first application may be one of the n applications in Table 3-1.

S3022 the terminal device determines the address of the first DNS server from the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application.

Here, if the identifier of the first application corresponds to an address of one DNS server, the address of the DNS server is the address of the first DNS server. Illustratively, still taking the "correspondence between different applications and different DNS servers" shown in table 3-1 as an example, the identifier of the first application is "FQDN _ 3". In table 3-1, there is a correspondence relationship between the application identified by "FQDN _ 3" and only the DNS server addressed to "IP @ 3", that is, only the DNS server addressed to "IP @ 3" can communicate with the application server deployed with "first application", and thus, the address of the first DNS server is "IP @ 3".

If the identifier of the first application corresponds to addresses of two or more DNS servers, the terminal device determines one DNS server from the plurality of DNS servers as the first DNS server based on a certain preset policy. Illustratively, the terminal device determines a first DNS server satisfying a preset policy from among a plurality of DNS servers. Wherein the preset policy comprises at least one of:

the first item: the priority of the first DNS server satisfies a priority condition among the priorities of the plurality of DNS servers. For example, the priority of the first DNS server is highest among the priorities of the plurality of DNS servers.

The second term is: the distance between the first DNS server and the terminal device satisfies a separation distance condition. For example, the distance between the first DNS server and the terminal device is less than or equal to a distance threshold value, or the distance between the first DNS server and the terminal device is the smallest among the distances between the plurality of DNS servers and the terminal device, respectively.

Illustratively, still taking the "correspondence between different applications and different DNS servers" shown in table 3-1 as an example, the identifier of the first application is "FQDN _ 1". In table 3-1, there is a correspondence between the application identified by "FQDN _ 1" and the DNS server addressed to "IP @ 2", respectively, that is, the DNS server addressed to "IP @ 1" and the DNS server addressed to "IP @ 2" are capable of resolving DNS request information corresponding to "first application". In the case where the preset policy is implemented as the second item, if the distance between the DNS server having the address "IP @ 1" and the terminal device satisfies the distance condition, the address of the first DNS server is "IP @ 1". If the distance between the DNS server with the address "IP @ 2" and the terminal device satisfies the distance condition, the address of the first DNS server is "IP @ 2".

Illustratively, referring to table 3-2, in addition to "correspondence between different applications and different DNS servers", the "priority of different DNS servers" is shown.

TABLE 3-2

Identification of applications	Address of DNS server	Priority level
			FQDN_1	IP@1	3
FQDN_1	IP@2	2
			FQDN_2	IP@1	3
FQDN_3	IP@3	4
			…	…	…
FQDN_n	IP@2	2

Referring to table 3-2, in table 3-2, the description of "correspondence between different applications and different DNS servers" may be referred to the description of table 3-1, and is not described herein again. In table 3-2, the priority of the DNS server addressed to "IP @ 1" is 3, the priority of the DNS server addressed to "IP @ 2" is 2, and the priority of the DNS server addressed to "IP @ 3" is 4. Here, in the column of "priority", the larger the numeric value is, the higher the corresponding priority is. Or conversely, the larger the value of the number is, the lower the corresponding priority is, and the embodiment of the present application does not limit this.

Taking the "correspondence between different applications and different DNS servers" shown in table 3-2 as an example, the identifier of the first application is "FQDN _ 1". In table 3-2, there is a correspondence between the application identified by "FQDN _ 1" and the DNS server addressed to "IP @ 1" and "IP @ 2", respectively. In the case where the preset policy is implemented as the first item, if the priority of the DNS server having the address "IP @ 1" is higher than that of the DNS server having the address "IP @ 2", the address of the first DNS server is "IP @ 1".

It should be noted that, in the embodiment of the present application, only the "priority" and the "distance" are taken as examples, and a specific implementation of the preset policy is exemplarily described. In the actual application process, other preset strategies may also be set according to the actual application requirements, which is not limited in the embodiment of the present application.

In this way, in the case where the SMF network element provides the terminal device with "the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application", the terminal device can determine the address of the first DNS server corresponding to the first application according to the information provided by the SMF network element.

S303, the terminal device determines the first address of the terminal device based on the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server.

The "address of the terminal apparatus" is described as follows: the terminal device may have one or more addresses. The address of the end device may be allocated by an SMF network element or by a upf (psa) network element. One address of the terminal device corresponds to one PSA network element and different addresses of the terminal device correspond to different PSA network elements. And the PSA network element corresponding to the first address of the terminal device is recorded as a first PSA network element.

The "address of the terminal device corresponding to the address of the first DNS server" is described as follows: because there is a correspondence between the PSA network element and the DNS server, the details are described in table 2. Furthermore, there is a correspondence between addresses of the PSA network element and the terminal device, which is described in detail in table 1. For the DNS server and the address of the terminal device that correspond to the same "PSA network element", there is also a correspondence between the two. For example, referring to table 4, table 4 shows "correspondence between DNS server and address of terminal device" taking "address of DNS server" as an example.

TABLE 4

Referring to table 4, table 4 shows (n +1) addresses of the terminal device, respectively noted as: address of terminal device @0, address of terminal device @1, …, address of terminal device @ n. The number of DNS servers is (n +1), and the addresses of (n +1) DNS servers are respectively noted as: IP @0, IP @1, IP @2, …, IP @ n. In table 4, there is a correspondence relationship between the addresses of the terminal apparatuses located on the same row and the DNS server. As shown in table 4, there is a correspondence between the "address @ 0" of the terminal device and the DNS server identified by the address "IP @ 0", there is a correspondence between the "address @ 1" of the terminal device and the DNS server identified by the address "IP @ 1", there is a correspondence between the "address @ 2" of the terminal device and the DNS server identified by the address "IP @ 2", …, and there is a correspondence between the "address @ n" of the terminal device and the DNS server identified by the address "IP @ n".

For example, also taking the "correspondence relationship between DNS server and address of terminal device" shown in table 4 as an example, if the address of the first DNS server is "IP @ 1", the first address of the terminal device is "address @1 of the terminal device". If the address of the first DNS server is "IP @ 2", the first address of the terminal device is "address @2 of the terminal device".

The information "the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server" may be information preconfigured by the terminal device, or may be information issued by an SMF network element, a PCF network element, or another network element for the terminal device, for example:

the SMF network element transmits the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server to the terminal device. Accordingly, the terminal device receives the address of the first DNS server from the SMF network element and the address of the terminal device corresponding to the address of the first DNS server.

Illustratively, during the process of inserting the BP device into the user plane path of the PDU session, the SMF network element sends the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server to the terminal device. For example, the information is carried in a routing rule (routing rule) issued to the terminal device.

S304, the terminal device transmits DNS request information to the BP apparatus. Accordingly, the BP device receives DNS request information from the terminal apparatus.

Wherein the DNS request information comprises an identity of the first application, an address of the first DNS server and a first address of the terminal device. Here, the source address of the DNS request information is the first address of the terminal device, and the destination address of the DNS request information is the address of the first DNS server.

Illustratively, the identifier of the first application is "FQDN _ 1", the address of the first DNS server is "IP @ 1", and the address of the terminal device is "address @ 1" of the terminal device. In this case, the identifier of the application in the DNS request information is "FQDN _ 1", the source address of the DNS request information is "address @ 1" of the terminal device, and the destination address of the DNS request information is "IP @ 1".

Illustratively, referring to fig. 5, the terminal apparatus transmits DNS request information to the BP device. Accordingly, the BP device receives DNS request information from the terminal apparatus. And then, the BP equipment determines the PSA network element corresponding to the source address according to the source address of the DNS request information, and then sends the DNS request information to the PSA network element corresponding to the source address. Correspondingly, the PSA network element corresponding to the source address receives the DNS request information from the BP equipment. Here, if the PSA network element corresponding to the source address is a "C-PSA" network element, the BP device sends DNS request information to the C-PSA network element. Accordingly, the C-PSA network element receives DNS request information from the BP device. And then, the C-PSA network element sends the DNS request information to a C-DNS server according to the destination address in the DNS request information. Correspondingly, the C-DNS server receives DNS request information from the C-PSA network element, analyzes the DNS request information and obtains response information aiming at the DNS request information. Wherein the response information includes the IP address of the application server. The response information is transmitted to the terminal device by the C-DNS server, the C-PSA network element and the BP equipment, and the IP address of the application server is provided for the terminal device, so that data transmission can be carried out between the terminal device and the application server. And if the PSA network element corresponding to the source address is an L-PSA network element, the BP equipment sends DNS request information to the L-PSA network element. Accordingly, the L-PSA network element receives DNS request information from the BP device. And then, the L-PSA network element sends the DNS request information to an L-DNS server according to the destination address in the DNS request information. Correspondingly, the L-DNS server receives DNS request information from the L-PSA network element, and analyzes the DNS request information to obtain response information of the DNS request information. And the response information is transmitted to the terminal device from the L-DNS server, the L-PSA network element and the BP equipment, and the IP address of the application server is provided for the terminal device.

It should be noted that, in the case where the location of the terminal device changes, the network device (e.g., an SMF network element or a PCF network element) provides the terminal device with "correspondence between different applications and different DNS servers" and "correspondence between a DNS server and an address of the terminal device".

In the method for sending a domain name system request according to the embodiment of the present application, after determining the address of the first DNS server corresponding to the first application, the terminal device may further determine the first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server. Since there is a correspondence between the address of the first DNS server and the first address of the terminal device, and the first address of the terminal device corresponds to one PSA network element, that is, communication is enabled between the first DNS server and the PSA network element corresponding to the first address of the terminal device. Because the DNS request information sent by the terminal device comprises the address of the first DNS server and the first address of the terminal device, the DNS request information can be transmitted to the first DNS server through the PSA network element corresponding to the terminal device, thereby improving the success rate of DNS analysis and reducing the phenomenon of 'DNS analysis failure' caused by 'no communication between the DNS server and the PSA network element' in the prior art.

The embodiment of the present application provides a second method for sending a domain name system request, where the method for sending a domain name system request is applied in a domain name resolution process. Referring to fig. 6, a method for sending a domain name system request according to an embodiment of the present application includes the following steps:

s601, the terminal device creates a PDU session.

For a specific implementation process of S601, reference may be made to the relevant description of S301, which is not described herein again.

S602, the terminal apparatus transmits DNS request information to the BP device. Accordingly, the BP device receives DNS request information from the terminal apparatus.

Wherein the DNS request information comprises an identity of the first application, a source address and a destination address. In S602, the source address and the destination address selected by the terminal device are not limited, and the specific implementation process may refer to the prior art, which is not described herein again.

S603, the BP equipment updates at least one of the source address and the destination address in the DNS request information to obtain the updated DNS request information.

The source address in the updated DNS request information is the first address of the terminal device, and the destination address in the updated DNS request information is the address of the first DNS server. Here, in the updated DNS request information, there is a correspondence between the PSA network element corresponding to the source address and the first DNS server, which enables communication, see the relevant description of S303, which is not described herein again, and a phenomenon of "DNS resolution failure" caused by the inability to communicate between the PSA network element and the DNS server is avoided.

There are various ways for "the BP device updates at least one of the source address and the destination address in the DNS request information to obtain updated DNS request information", and three examples are described below:

example one, a BP device updates at least one of a source address and a destination address in DNS request information according to an identifier of a first application in the DNS request information, to obtain updated DNS request information.

Here, the source address and the destination address in the updated DNS request information are determined according to the identifier of the first application, and the application server corresponding to the first application is deployed in the data network corresponding to the first DNS server, so that the first DNS server can resolve the DNS request information. After the first DNS server is determined, the PSA network element corresponding to the first DNS server can be determined, the first address of the terminal device is further determined, and communication can be performed between the PSA network element corresponding to the first address of the terminal device and the first DNS server, so that DNS request information analysis efficiency is improved.

Exemplarily, referring to fig. 7, in order to obtain the updated DNS request information, the BP device performs the following steps:

s6031, the BP device determines an address of the first DNS server corresponding to the identifier of the first application.

For example, the BP device may determine the address of the first DNS server corresponding to the first application according to "correspondence between different applications and different DNS servers". Here, for the description of "correspondence between different applications and different DNS servers", reference may be made to the relevant description of S302, and details are not described here. S6031 may be specifically implemented as the following step one and step two:

step one, the SMF network element sends the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application to the BP equipment. Correspondingly, the BP device receives the identifier of the first application from the SMF network element and the address of the DNS server corresponding to the identifier of the first application.

Alternatively, step one can also be implemented as: and the SMF network element sends the identification of the application deployed in the data network to the BP equipment. Accordingly, the BP device receives an identification of an application deployed in the data network from the SMF network element. Alternatively, step one can also be implemented as: and the SMF network element sends the identification of the application server deployed in the data network to the BP equipment. Accordingly, the BP device receives an identification of an application server deployed in the data network from the SMF network element. As described above, if there is a correspondence between the data network and the DNS server, the BP device can determine the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application according to the information received from the SMF network element.

And step two, the BP equipment determines the address of the first DNS according to the identifier of the first application and the address of the DNS corresponding to the identifier of the first application.

Here, the description of step two may refer to the related description of S3022. That is, the BP device replaces the terminal apparatus in S3022, and the specific method flow is the same, which is not described herein again.

After the BP device determines the address of the first DNS server, if the destination address in the DNS request information coincides with the address of the first DNS server, the BP device need not perform S6032. If the destination address in the DNS request information does not coincide with the address of the first DNS server, the BP device executes S6032:

s6032, the BP device updates the destination address in the DNS request information to the address of the first DNS server.

Illustratively, if the address of the first DNS server is "IP @ 2" and the destination address in the DNS request message is "IP @ 3", the BP device replaces the destination address in the DNS request message with "IP @ 2".

S6033, the BP device determines the first address of the terminal apparatus from the address of the first DNS server and the address of the terminal apparatus corresponding to the address of the first DNS server.

Here, the description about S6033 may refer to the related description of S303. That is, the BP device replaces the terminal apparatus in S303, and the specific method flow is the same, which is not described herein again.

After the BP apparatus determines the first address of the terminal device, if the source address in the DNS request information coincides with the first address of the terminal device, the BP apparatus need not perform S6034. If the source address in the DNS request message does not match the first address of the terminal apparatus, the BP apparatus executes S6034:

s6034, the BP apparatus sets the source address in the DNS request information as the first address of the terminal device.

Illustratively, if the first address of the terminal device is "address of terminal device @ 2" and the source address in the DNS request information is "address of terminal device @ 3", the BP equipment replaces the source address in the DNS request information with "address of terminal device @ 2".

In this way, the BP device updates the source address and the destination address in the DNS request information to obtain updated DNS request information, subject to the identifier of the application in the DNS request information.

In the second example, the BP device updates the destination address in the DNS request information according to the source address in the DNS request information.

Illustratively, still taking the "correspondence relationship existing between the DNS server and the address of the terminal device" shown in table 4 as an example, in the case where the source address in the DNS request information is "address of the terminal device @ 1" and the destination address in the DNS request information is not "IP @ 1", the BP device updates the destination address in the DNS request information to "IP @ 1". In the case where the source address in the DNS request information is "address of terminal device @ 2" and the destination address in the DNS request information is not "IP @ 2", the BP device updates the destination address in the DNS request information to "IP @ 2".

Here, the BP device updates the destination address in the DNS request information to obtain updated DNS request information, subject to the source address in the DNS request information.

In example two, as a possible implementation manner, the BP device performs the following step three and step four:

and step three, if the source address in the DNS request information is the first address of the terminal device, the BP equipment determines the address of the first DNS server according to the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device.

Illustratively, still taking the "correspondence relationship existing between the DNS server and the address of the terminal device" shown in table 4 as an example, in the case where the source address in the DNS request information is "address of terminal device @ 1", the BP device determines the address of the first DNS server as "IP @ 1" in conjunction with table 4. In the case where the source address in the DNS request information is "address of terminal device @ 2", the BP device determines that the address of the first DNS server is "IP @ 2".

Here, the information "the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device" may be information preconfigured by the BP device, or may be information issued by the SMF network element for the BP device, that is: and the SMF network element sends the first address of the terminal device and the address of the DNS corresponding to the first address of the terminal device to the BP equipment. Accordingly, the BP device receives the first address of the terminal device from the SMF network element and the address of the DNS server corresponding to the first address of the terminal device.

And step four, the BP equipment updates the destination address in the DNS request information into the address of the first DNS server.

Illustratively, in the case where the source address in the DNS request information is "address of terminal device @ 1" and the destination address in the DNS request information is not "IP @ 1", the BP device updates the destination address in the DNS request information to "IP @ 1". In the case where the source address in the DNS request information is "address of terminal device @ 2" and the destination address in the DNS request information is not "IP @ 2", the BP device updates the destination address in the DNS request information to "IP @ 2".

In this way, when determining that the source address in the DNS request information is the first address of the terminal device, the BP device updates the destination address in the DNS request information, with the source address in the DNS request information as the standard, to obtain the updated DNS request information.

And in the third example, the BP equipment updates the source address in the DNS request information according to the destination address in the DNS request information.

Illustratively, still taking the "correspondence relationship existing between the DNS server and the address of the terminal device" shown in table 4 as an example, in the case where the destination address in the DNS request information is "IP @ 1" and the source address in the DNS request information is not "address of terminal device @ 1", the BP device updates the source address in the DNS request information to "address of terminal device @ 1". In the case where the destination address in the DNS request information is "IP @ 2" and the source address in the DNS request information is not "address of terminal device @ 2", the BP equipment updates the source address in the DNS request information to "address of terminal device @ 2".

Here, the BP device updates the source address in the DNS request information to obtain updated DNS request information, subject to the destination address in the DNS request information.

In example three, as a possible implementation manner, the BP device performs the following step five and step six:

and step five, if the destination address in the DNS request information is the address of the first DNS server, the BP equipment determines the first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server.

Illustratively, still taking the "correspondence relationship existing between the DNS server and the address of the terminal device" shown in table 4 as an example, in the case where the destination address in the DNS request information is "IP @ 1", the BP device determines, in combination with table 4, that the first address of the terminal device is "address @1 of the terminal device". In the case where the destination address in the DNS request message is "IP @ 2", the BP device determines, in conjunction with table 4, that the first address of the terminal apparatus is "address @2 of the terminal apparatus".

Here, the information "the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server" may be information preconfigured by the BP device, or may be information issued by the SMF network element for the BP device, that is: the SMF network element sends the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server to the BP equipment. Accordingly, the BP device receives an address of a first DNS server of the terminal device from the SMF network element and an address of the terminal device corresponding to the address of the first DNS server.

And step six, the BP equipment updates the source address in the DNS request information into the first address of the terminal device.

Illustratively, in the case where the destination address in the DNS request information is "IP @ 1" and the source address in the DNS request information is not "address of terminal device @ 1", the BP device updates the source address in the DNS request information to "address of terminal device @ 1". In the case where the destination address in the DNS request information is "IP @ 2" and the source address in the DNS request information is not "address of terminal device @ 2", the BP equipment updates the source address in the DNS request information to "address of terminal device @ 2".

In this way, when determining that the destination address in the DNS request information is the address of the first DNS server, the BP device updates the source address in the DNS request information, with reference to the destination address in the DNS request information, to obtain updated DNS request information.

It should be noted that, in the first example, the update rule of the BP device is "update at least one of the source address and the destination address in the DNS request information with reference to the identifier of the first application in the DNS request information". In the second example, the update rule of the BP device is "update the destination address in the DNS request information with reference to the source address in the DNS request information". In the third example, the update rule of the BP device is "update the source address in the DNS request information with reference to the destination address in the DNS request information". The update rule in any of the above three examples may be configured in advance on the BP device, or may be configured by the SMF network element for the BP device. The update rule of any of the three examples described above may be configured with the terminal device as a granularity, that is, the update rule of different DNS request information sent by the same terminal device is the same, and the update rule of DNS request information for different terminal devices may be the same or different. In this case, if N terminal apparatuses are all served by the BP device, the BP device needs to configure the update rule N times. The update rule of any of the above three examples may also be that "BP device" is configured for granularity, that is, for one BP device, the BP device updates the source address and/or the destination address in the DNS request information by using the same update rule. In this case, if N terminal apparatuses are all served by the BP device, the BP device needs to configure 1 update rule.

S604, the BP device sends the updated DNS request information to the first PSA network element according to the source address in the updated DNS request information. Accordingly, the first PSA network element receives updated DNS request information from the BP device.

Wherein the first PSA network element is a PSA network element corresponding to a first address of the terminal device.

For example, the BP device determines the first PSA network element according to the source address in the updated DNS request information, and then sends the updated DNS request information to the first PSA network element, where the specific implementation process may refer to the prior art and is not described herein again.

S605, the first PSA network element sends the updated DNS request information to the first DNS server according to the destination address in the updated DNS request information. Accordingly, the first DNS server receives updated DNS request information from the first PSA network element.

And the first DNS server and the first PSA network element have a corresponding relation.

S606, the first DNS server analyzes the updated DNS request information to obtain response information.

Wherein the DNS request information comprises an identification of the first application. Correspondingly, the response message includes the IP address of the application server corresponding to the first application. The source address of the response message is the destination address of the updated DNS request message, and the destination address of the response message is the source address of the updated DNS request message, and the specific implementation process of S606 may refer to the prior art, and is not described herein again.

S607, the first DNS server sends response information to the first PSA network element. Accordingly, the first PSA network element receives the response information from the first DNS server.

Illustratively, the destination address of the response message is the source address of the updated DNS request message, i.e. the first address of the terminal device. The first DNS server sends the response message to the first PSA network element according to the destination address of the response message, and the specific implementation process may refer to the prior art, which is not described herein again.

And S608, the first PSA network element sends response information to the BP equipment. Accordingly, the BP device receives the response information from the first PSA network element.

Here, the source address of the response message is the destination address of the updated DNS request message, and the destination address of the response message is the source address of the updated DNS request message.

S609, the BP equipment updates at least one of the source address and the destination address in the response information to obtain the updated response information.

And the source address in the updated response information is the destination address of the DNS request information before updating, and the destination address in the updated response information is the source address of the DNS request information before updating.

For example, if the BP device replaces the source address in the DNS request message with "the address of the terminal device @ 2" from "the address of the terminal device @ 3" in S603, the BP device replaces the destination address in the response message with "the address of the terminal device @ 3" from "the address of the terminal device @ 2" in S609. If the BP device replaces the destination address in the DNS request message from "IP @ 1" to "IP @ 2" in S603, the BP device replaces the source address in the response message from "IP @ 2" to "IP @ 1" in S609.

S610, the BP device transmits the updated response information to the terminal apparatus. Accordingly, the terminal apparatus receives the updated response information from the BP device.

Here, the updated response information includes the IP address of the application server corresponding to the first application, the destination address of the DNS request information before update, and the source address of the DNS request information before update. After the terminal device executes S602 to send the DNS request information, it monitors a response message carrying a source address and a destination address of the DNS request information before updating. The BP device can replace at least one of the source address and the destination address in the response information to ensure that the terminal device can monitor the response message carrying the source address and the destination address of the DNS request information before updating.

In the sending method for domain name system request in the embodiment of the application, after the BP device receives the DNS request information from the terminal device, the BP device can update at least one of the source address and the destination address in the DNS request information to obtain the updated DNS request information, and then send the updated DNS request information. Since the source address in the updated DNS request information is the first address of the terminal device, the destination address in the updated DNS request information is the address of the first DNS server. The first PSA network element corresponding to the first address of the terminal device can communicate with the first DNS server, so that the updated DNS request information can be transmitted to the first DNS server through the first PSA network element, thereby improving the success rate of DNS analysis and reducing the phenomenon of DNS analysis failure caused by 'no communication between the DNS server and the PSA network element' in the prior art.

The embodiment of the application provides a third method for sending a domain name system request, which is applied to a domain name resolution process. Referring to fig. 8, a method for sending a domain name system request according to an embodiment of the present application includes the following steps:

s801, the terminal device creates a PDU session.

For a specific implementation process of S801, reference may be made to the relevant description of S301, which is not described herein again. As shown in table 1, the terminal apparatus is assigned a plurality of addresses. Wherein one of the plurality of addresses corresponds to one PSA network element and different ones of the plurality of addresses correspond to different PSA network elements.

It should be noted that, in the process of inserting the BP device and the L-PSA network element into the user plane path of the PDU session, the SMF network element issues forwarding rule information to the C-PSA network element and the L-PSA network element, respectively, so as to instruct the C-PSA network element and the L-PSA network element to send data packets to the BP device when receiving data packets of a specific destination address. Specifically, the forwarding rule information issued to the C-PSA network element is used to instruct the C-PSA network element to send a data packet to the BP device when receiving a data packet whose destination address is "address @1 of the terminal device", "address @2 of the terminal device", … "address @ n of the terminal device". If the terminal device distributes N addresses, the number of the corresponding destination addresses in the forwarding rule information issued to the C-PSA network element is (N-1). Of course, a plurality of destination addresses may be combined in one piece of forwarding rule information, or may be borne in different pieces of forwarding rule information, and transmitted to the C-PSA network element, which is not limited in this embodiment of the present application. Similarly, when sending the forwarding rule information to one of the L-PSA network elements, taking the L-PSA _1 network element as an example, the following description is made: and forwarding rule information which is issued to the L-PSA _1 network element and is used for indicating the L-PSA _1 network element to send the data packet to the BP equipment when receiving the data packet with the destination address of ' the address of the terminal device @1 ', ' the address of the terminal device @2 ', … ' and ' the address of the terminal device @ n '. If the terminal device allocates N addresses, the number of the corresponding destination addresses in the forwarding rule information issued to the L-PSA _1 network element is (N-1). Of course, a plurality of destination addresses may be combined in one piece of forwarding rule information, or may be borne in different pieces of forwarding rule information, and transmitted to the L-PSA _1 network element, which is not limited in this embodiment of the present application. For sending the forwarding rule information to other network elements in the L-PSA network element, reference may be made to the above description, which is not described herein again.

S802, the terminal apparatus transmits DNS request information to the BP device. Accordingly, the BP device receives DNS request information from the terminal apparatus.

Wherein the DNS request information comprises an identity of the first application, a source address and a destination address. Wherein, the source address of the DNS request information is the second address of the terminal device and corresponds to the second PSA network element. The destination address of the DNS request message is the address of the first DNS server, corresponding to the first PSA network element.

For example, taking the "correspondence between the address of the terminal device and the PSA network element" shown in table 1 and the "correspondence between the PSA network element and the DNS server" shown in table 2 as an example, if the source address of the DNS request message is "address of the terminal device @ 0", and the destination address of the DNS request message is "IP @ 1". In this case, the first DNS server is an "L-DNS _ 1" server, and the second PSA network element is a "C-PSA" network element. If the source address of the DNS request message is "address of terminal device @ 1", the destination address of the DNS request message is "IP @ 0". In this case, the first DNS server is a "C-DNS" server, and the second PSA network element is an "L-PSA _ 1" network element.

And S803, the BP equipment sends DNS request information to a first PSA network element corresponding to the destination address according to the destination address in the DNS request information. Accordingly, the first PSA network element receives DNS request information from the BP device.

Illustratively, taking the "correspondence between the PSA network element and the DNS server" shown in table 2 as an example, if the destination address of the DNS request message is "IP @ 0", the first PSA network element is a "C-PSA" network element. And the BP equipment sends DNS request information to a C-PSA network element. And if the destination address of the DNS request message is 'IP @ 1', the first PSA network element is an 'L-PSA _ 1' network element. And the BP equipment sends DNS request information to an L-PSA _1 network element.

S804, the first PSA network element sends DNS request information to the first DNS server. Accordingly, the first DNS server receives DNS request information from the first PSA network element.

Illustratively, the first PSA network element sends the DNS request information to the first DNS server according to the destination address in the DNS request information. And if the first PS A network element is a C-PSA network element, the first DNS server is a C-DNS server. The "C-PSA" network element sends DNS request information to a "C-DNS" server. And if the first PSA network element is an L-PSA _1 network element, the first server is an L-DNS server. The "L-PSA" network element sends DNS request information to the "L-DNS" server. The specific implementation process of S804 may refer to the prior art, and is not described herein again.

And S805, the first DNS server analyzes the DNS request information to obtain response information.

Wherein the DNS request information comprises an identification of the first application. Correspondingly, the response message includes the IP address of the application server corresponding to the first application. The source address of the response message is the destination address of the DNS request message, and the destination address of the response message is the source address of the DNS request message, and the specific implementation process of S805 may refer to the prior art, which is not described herein again.

And S806, the first DNS server sends response information to the first PSA network element. Accordingly, the first PSA network element receives the response information from the first DNS server.

The source address of the response message is the address of the first DNS server, and the destination address of the response message is the second address of the terminal device. The second address of the terminal device corresponds to the second PSA network element. Here, S806 may be specifically implemented as the following process:

the first PSA network element receives response information for the DNS request information from the first DNS server through the tunnel between the first PSA network element and the first DNS server.

Wherein a tunnel is established between the first PSA network element and the first DNS server. In the case where the destination address of the response message is the second address of the terminal device and the source address of the response message is the address of the first DNS server, since the second address of the terminal device corresponds to the second PSA network element, the response message may be transmitted through a tunnel between the first PSA network element and the first DNS server.

Illustratively, the destination address of the response message is "address of terminal device @ 0", and the source address of the response message is "IP @ 1". In this case, the first DNS server is an "L-DNS _ 1" server, and the first PSA network element is an "L-PSA _ 1" network element. Since the response information can be transmitted from the first DNS server to the first PSA network element through the tunnel. Therefore, in addition to carrying the source address and the destination address, the response message also needs to encapsulate an address of the tunnel between the first PSA network element and the first DNS server to shield the destination address in the response message, so that the response message can be transmitted from the first DNS server to the first PSA network element.

And S807, the first PSA network element sends response information to the BP equipment according to the forwarding rule information. Accordingly, the BP device receives the response information from the first PSA network element.

For a description of the forwarding rule information, reference may be made to the introduction of S801, which is not described herein again. And the first PSA network element sends response information to the BP equipment based on the forwarding rule information. Here, the forwarding rule information instructs the first PSA network element to send a packet with a destination address as the second address to the BP device. The data packet includes the above-mentioned response information.

The forwarding rule information may be preconfigured information or information configured by the SMF network element for the first PSA. That is, the SMF network element sends forwarding rule information to the first PSA network element. Accordingly, the first PSA network element receives forwarding rule information from the SMF network element.

S808, the BP device transmits response information to the terminal apparatus. Accordingly, the terminal apparatus receives the response information from the BP device.

Here, the response information includes an IP address of an application server corresponding to the first application, a destination address of the DNS request information, and a source address of the DNS request information.

In the sending method for domain name system request in the embodiment of the present application, after receiving DNS request information from a terminal device, a BP device sends the DNS request information to a first PSA network element corresponding to a destination address according to the destination address in the DNS request information. Because the destination address of the DNS request information corresponds to the first PSA network element, the destination address of the DNS request information is the address of the first DNS server, and the first DNS server and the first PSA network element can communicate with each other, a phenomenon of "DNS resolution failure" caused by "no communication between the DNS server and the PSA network element" in the prior art can be reduced, and the success rate of DNS resolution is improved. In the process of feeding back the response information by the first DNS server, after the first PSA network element receives the response information from the first DNS server, even if the destination address of the response information is the second address of the terminal device and corresponds to the second PSA network element, the first PSA network element can transmit the response information to the BP device according to the forwarding rule information, so that the response information can be provided to the terminal device by the BP device.

The above-mentioned scheme provided by the embodiment of the present application is introduced mainly from the perspective of interaction between network elements. Correspondingly, the embodiment of the present application further provides a sending device for a domain name system request, where the sending device for the domain name system request may be a network element in the foregoing method embodiment, or a device including the foregoing network element, or a component that can be used for the network element. It is understood that the sending device of the domain name system request includes a hardware structure and/or a software module corresponding to each function in order to realize the above functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Fig. 9 is a schematic diagram illustrating a structure of a device 900 for sending a domain name system request. The sending device 900 for the domain name system request includes a transceiver module 901 and a processing module 902.

For example, taking the sending device 900 of the domain name system request as the terminal device in fig. 3 in the above method embodiment as an example,

the processing module 902 is configured to determine an address of a first domain name system DNS server corresponding to a first application. The processing module 902 is further configured to determine a first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server. The transceiver module 901 is configured to send DNS request information. Wherein the DNS request information comprises an identity of the first application, an address of the first DNS server and a first address of the terminal device.

In one possible design, the transceiver module 901 is further configured to receive an address of a first DNS server from the session management function SMF network element and an address of the terminal device corresponding to the address of the first DNS server.

In one possible design, the transceiver module 901 is configured to receive an identifier of a first application from an SMF network element and an address of a DNS server corresponding to the identifier of the first application. The processing module 902 is configured to determine an address of the first DNS server according to the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application.

In one possible design, the identification of the first application corresponds to a plurality of DNS servers. The processing module 902 is specifically configured to: a first DNS server satisfying a preset policy is determined from a plurality of DNS servers. Wherein the preset policy comprises at least one of: the priority of the first DNS server meets a priority condition among the priorities of the plurality of DNS servers; the distance between the first DNS server and the terminal device satisfies a separation distance condition.

For example, taking the sending apparatus 900 of the domain name system request as the BP device in fig. 6 in the above method embodiment as an example,

the transceiver module 901 is configured to receive domain name system DNS request information from a terminal device. The processing module 902 is configured to update at least one of a source address and a destination address in the DNS request information, so as to obtain updated DNS request information. The source address in the updated DNS request information is the first address of the terminal device, and the destination address in the updated DNS request information is the address of the first DNS server. The transceiving module 901 is further configured to send the updated DNS request information to the first packet data unit session anchor PSA network element according to the source address in the updated DNS request information. The first PSA network element corresponds to a first address of the terminal device, and the updated DNS request information is sent to the first DNS server by the first PSA network element according to the destination address in the updated DNS request information.

In one possible design, the processing module 902 is specifically configured to: and updating at least one of a source address and a destination address in the DNS request information according to the identification of the first application in the DNS request information, or updating the destination address in the DNS request information according to the source address in the DNS request information, or updating the source address in the DNS request information according to the destination address in the DNS request information.

In one possible design, the processing module 902 is specifically configured to: determining an address of a first DNS server corresponding to the identifier of the first application; updating the destination address in the DNS request information into the address of the first DNS server; determining a first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server; the source address in the DNS request information is the first address of the terminal device.

In one possible design, the transceiver module 901 is configured to receive an identification of a first application from a session management function, SMF, network element and an address of a DNS server corresponding to the identification of the first application. The processing module 902 is configured to determine an address of the first DNS server according to the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application.

In one possible design, the processing module 902 is specifically configured to: if the destination address in the DNS request information is the address of the first DNS server, the first address of the terminal device is determined from the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server, and the source address in the DNS request information is updated to the first address of the terminal device.

In one possible design, the transceiver module 901 is further configured to receive an address of a first DNS server from the SMF network element and an address of the terminal device corresponding to the address of the first DNS server.

In one possible design, the processing module 902 is specifically configured to: if the source address in the DNS request information is the first address of the terminal device, the address of the first DNS server is determined according to the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device, and the destination address in the DNS request information is updated to the address of the first DNS server.

In one possible design, the transceiver module 901 is further configured to receive a first address of a terminal device from the SMF network element and an address of a DNS server corresponding to the first address of the terminal device.

In one possible design, the transceiver module 901 is further configured to receive response information from the first PSA network element for the DNS request information. The processing module 902 is configured to update at least one of a source address and a destination address in the response message, so as to obtain an updated response message. And the source address in the updated response information is the destination address of the DNS request information before updating, and the destination address in the updated response information is the source address of the DNS request information before updating. The transceiver module 901 is further configured to send the updated response information to the terminal device.

For example, the sending apparatus 900 for domain name system request is used as an example of the method embodiment described above, and fig. 8 is executed by the BP device,

the transceiver module 901 is configured to receive domain name system DNS request information from a terminal device. The transceiver module 901 is further configured to send, according to a destination address in the DNS request information, the DNS request information to a first packet data unit session anchor PSA network element corresponding to the destination address, so that the DNS request information is sent to the first DNS server by the first PSA network element.

For example, the sending apparatus 900 for domain name system request is used as an example in the above method embodiment, fig. 8 is executed by the first PSA network element,

the transceiving module 901 is configured to send DNS request information to the first domain name system DNS server. Wherein the DNS request information includes an address of the first DNS server and a second address of the terminal device corresponding to the second PSA network element. The transceiver module 901 is further configured to receive response information from the first DNS server for the DNS request information. The processing module 902 is configured to enable the transceiver module 901 to send response information to the branch point BP device according to the forwarding rule information. The forwarding rule information is used for instructing the first PSA network element to send a data packet with a destination address as a second address to the BP equipment; the data packet includes response information.

In one possible design, the transceiver module 901 is configured to receive forwarding rule information from a session management function, SMF, network element.

In one possible design, the transceiver module 901 is configured to receive response information for the DNS request information from the first DNS server through a tunnel between the first PSA network element and the first DNS server.

All relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

It should be understood that the processing module 902 in the embodiments of the present application may be implemented by a processor or a processor-related circuit component, and the transceiver module 901 may be implemented by a transceiver or a transceiver-related circuit component.

Optionally, the sending device 900 of the domain name system request may further include a storage module 903, which is used for storing the program code and data of the device 900, and the data may include, but is not limited to, original data or intermediate data, etc.

In one possible approach, the processing module 902 may be a processor or a controller, such as a Central Processing Unit (CPU), a general purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. A processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, a DSP and a microprocessor, or the like. The transceiver module 901 may be a transceiver, a transceiver circuit or a communication interface, etc. The storage module 903 may be a memory.

In a possible manner, when the processing module 902 is a processor, the transceiver module 901 is a communication interface, and the storage module 903 is a memory, the configuration of the sending apparatus for domain name system request according to the embodiment of the present application may be as shown in fig. 10.

Fig. 10 shows a simplified schematic diagram of a possible design structure of a domain name system request sending apparatus according to an embodiment of the present application. The apparatus 1000 for sending a domain name system request includes: processor 1002, communication interface 1003, memory 1001. Optionally, the sending apparatus 1000 of the domain name system request may further include a bus 1004. The communication interface 1003, the processor 1002, and the memory 1001 may be connected to each other via a bus 1004. The bus 1004 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 1004 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one line is shown in FIG. 10, but it is not intended that there be only one bus or one type of bus.

Those of ordinary skill in the art will understand that: in the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions according to the embodiments of the present application are all or partially generated when the computer program instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, a division of modules is merely a division of logical functions, and an actual implementation may have another division, for example, a plurality of modules or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or modules through some interfaces, and may be in an electrical or other form.

Modules described as separate parts may or may not be physically separate, and parts displayed as modules may or may not be physical modules, may be located in one place, or may be distributed on a plurality of network devices (for example, terminal apparatuses). Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

In addition, each functional module in the embodiments of the present application may be integrated into one processing module, or each functional module may exist independently, or two or more functional modules may be integrated into one module. The integrated module can be realized in a hardware form, and can also be realized in a form of hardware and a software functional module.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present application can be implemented by software plus necessary general hardware, and certainly, the present application can also be implemented by hardware, but in many cases, the former is a better implementation. Based on such understanding, the technical solutions of the present application may be substantially implemented or a part of the technical solutions contributing to the prior art may be embodied in the form of a software product, where the computer software product is stored in a readable storage medium, such as a floppy disk, a hard disk, or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods described in the embodiments of the present application.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and all changes and substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for sending a Domain Name System (DNS) request is characterized by comprising the following steps:

the terminal device determines the address of a first DNS server corresponding to the first application;

the terminal device determines a first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server;

the terminal device sends DNS request information, wherein the DNS request information comprises the identification of the first application, the address of the first DNS server and the first address of the terminal device.

2. The method of claim 1, further comprising:

the terminal device receives the address of the first DNS server from a Session Management Function (SMF) network element and the address of the terminal device corresponding to the address of the first DNS server.

3. The method according to claim 1 or 2, wherein the determining, by the terminal device, the address of the first DNS server corresponding to the first application comprises:

the terminal device receives an identifier of the first application from an SMF network element and an address of a DNS (domain name server) corresponding to the identifier of the first application;

and the terminal device determines the address of the first DNS according to the identifier of the first application and the address of the DNS corresponding to the identifier of the first application.

4. The method according to claim 3, wherein the identifier of the first application corresponds to a plurality of DNS servers, and the determining, by the terminal device, the address of the first DNS server according to the identifier of the first application and the address of the DNS server corresponding to the identifier of the first application comprises:

the terminal device determines the first DNS server meeting a preset strategy from the plurality of DNS servers;

wherein the preset policy comprises at least one of:

the priority of the first DNS server satisfies a priority condition among the priorities of the plurality of DNS servers;

the distance between the first DNS server and the terminal device satisfies a separation distance condition.

5. A method for sending a Domain Name System (DNS) request is characterized by comprising the following steps:

a branch point BP device receives domain name system DNS request information from a terminal device;

the BP equipment updates at least one of a source address and a destination address in the DNS request information to obtain updated DNS request information, wherein the source address in the updated DNS request information is a first address of the terminal device, and the destination address in the updated DNS request information is an address of a first DNS server;

the BP equipment sends the updated DNS request information to a first packet data unit session anchor point PSA network element according to a source address in the updated DNS request information; the first PSA network element corresponds to a first address of the terminal device; and the destination address in the updated DNS request information enables the updated DNS request information to be sent to the first DNS server by the first PSA network element.

6. The method of claim 5, wherein the BP device updating at least one of a source address and a destination address in the DNS request information comprises:

the BP equipment updates at least one of a source address and a destination address in the DNS request information according to the identifier of the first application in the DNS request information;

or the BP equipment updates the destination address in the DNS request information according to the source address in the DNS request information;

or the BP device updates the source address in the DNS request information according to the destination address in the DNS request information.

7. The method of claim 6, wherein the BP device updating at least one of a source address and a destination address in the DNS request information according to the identity of the first application in the DNS request information comprises:

the BP equipment determines the address of the first DNS server corresponding to the identifier of the first application;

the BP equipment updates the destination address in the DNS request information into the address of the first DNS server;

the BP equipment determines a first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server;

and the BP equipment takes the source address in the DNS request information as the first address of the terminal device.

8. The method of claim 7, wherein the determining, by the BP device, the address of the first DNS server corresponding to the identity of the first application comprises:

the BP equipment receives an identifier of the first application from a Session Management Function (SMF) network element and an address of a DNS (domain name server) corresponding to the identifier of the first application;

and the BP equipment determines the address of the first DNS according to the identifier of the first application and the address of the DNS corresponding to the identifier of the first application.

9. The method of claim 6, wherein the BP device updates a source address in the DNS request information according to a destination address in the DNS request information, comprising:

if the destination address in the DNS request information is the address of the first DNS server, the BP device determines the first address of the terminal device according to the address of the first DNS server and the address of the terminal device corresponding to the address of the first DNS server;

and the BP equipment updates the source address in the DNS request information into the first address of the terminal device.

10. The method according to any one of claims 7 to 9, further comprising:

the BP equipment receives the address of the first DNS server from an SMF network element and the address of the terminal device corresponding to the address of the first DNS server.

11. The method of claim 6, wherein the BP device updates the destination address in the DNS request information according to the source address in the DNS request information, comprising:

if the source address in the DNS request information is the first address of the terminal device, the BP device determines the address of the first DNS server according to the first address of the terminal device and the address of the DNS server corresponding to the first address of the terminal device;

and the BP equipment updates the destination address in the DNS request information into the address of the first DNS server.

12. The method of claim 11, further comprising:

and the BP equipment receives the first address of the terminal device from the SMF network element and the address of the DNS server corresponding to the first address of the terminal device.

13. The method according to any one of claims 5 to 12, further comprising:

the BP equipment receives response information aiming at the DNS request information from the first PSA network element;

the BP equipment updates at least one of a source address and a destination address in the response information to obtain updated response information, wherein the source address in the updated response information is the destination address of the DNS request information before updating, and the destination address in the updated response information is the source address of the DNS request information before updating;

and the BP equipment sends the updated response information to the terminal device.

14. The method of claim 13,

the DNS request information comprises an identification of a first application;

the response information includes an internet protocol, IP, address of an application server corresponding to the first application.

15. A method for sending a Domain Name System (DNS) request is characterized by comprising the following steps:

and the BP equipment sends the DNS request information to a first packet data unit session anchor point PSA network element corresponding to the destination address according to the destination address in the DNS request information, so that the DNS request information is sent to a first DNS server by the first PSA network element.

16. A method for sending Domain Name System (DNS) request information is characterized by comprising the following steps:

a first packet data unit (PSA) network element serving as a session anchor sends DNS request information to a first Domain Name System (DNS) server, wherein the DNS request information comprises an address of the first DNS server and a second address of a terminal device corresponding to a second PSA network element;

the first PSA network element receiving response information from the first DNS server for the DNS request information;

the first PSA network element sends the response information to a branch point BP device according to forwarding rule information, wherein the forwarding rule information is used for indicating the first PSA network element to send a data packet with a destination address as the second address to the BP device; the data packet includes the response information.

17. The method of claim 16, further comprising:

and the first PSA network element receives the forwarding rule information from a Session Management Function (SMF) network element.

18. The method according to claim 16 or 17, wherein the first PSA network element receiving response information from the first DNS server for the DNS request information comprises:

the first PSA network element receives response information from the first DNS server for the DNS request information through a tunnel between the first PSA network element and the first DNS server.

19. The method according to any one of claims 16 to 18,

the DNS request information comprises an identification of a first application;

20. A device for sending a domain name system DNS request, comprising: means for performing the steps of any of claims 1 to 4.

21. A device for sending a domain name system DNS request, comprising: a processor for calling a program in a memory to cause the apparatus for sending a domain name system DNS request to execute the method for sending a domain name system DNS request according to any one of claims 1 to 4.

22. A device for sending a domain name system DNS request, comprising: a processor and an interface circuit for communicating with other devices, the processor being configured to perform the method of sending a domain name system, DNS, request according to any of claims 1 to 4.

23. A device for sending a domain name system DNS request, comprising: means for performing the steps of any of claims 5 to 14.

24. A device for sending a domain name system DNS request, comprising: a processor configured to call a program in a memory to cause the apparatus for sending a domain name system DNS request to execute the method for sending a domain name system DNS request according to any one of claims 5 to 14.

25. A device for sending a domain name system DNS request, comprising: a processor and an interface circuit for communicating with other devices, the processor being configured to perform the method of sending a domain name system, DNS, request according to any of claims 5 to 14.

26. A device for sending a domain name system DNS request, comprising: means for performing the steps recited in claim 15.

27. A device for sending a domain name system DNS request, comprising: a processor for calling a program in a memory to cause the apparatus for sending a domain name system DNS request to execute the method for sending a domain name system DNS request according to claim 15.

28. A device for sending a domain name system DNS request, comprising: a processor and an interface circuit for communicating with other devices, the processor being configured to perform the method for sending a domain name system, DNS, request of claim 15.

29. A device for sending a domain name system DNS request, comprising: means for performing the steps of any of claims 16 to 19.

30. A device for sending a domain name system DNS request, comprising: a processor for calling a program in a memory to cause the apparatus for sending a domain name system DNS request to execute the method for sending a domain name system DNS request according to any one of claims 16 to 19.

31. A device for sending a domain name system DNS request, comprising: a processor and interface circuitry for communicating with other devices, the processor being configured to perform the method of sending a domain name system, DNS, request according to any of claims 16 to 19.

32. A computer-readable storage medium characterized in that it stores a program that, when invoked by a processor, executes the method of sending a domain name system DNS request according to any one of claims 1 to 4, or executes the method of sending a domain name system DNS request according to any one of claims 5 to 14, or executes the method of sending a domain name system DNS request according to claim 15, or executes the method of sending a domain name system DNS request according to any one of claims 16 to 19.

33. A computer program, characterized in that, when the program is invoked by a processor, the method of sending a domain name system DNS request according to any one of claims 1 to 4 is executed, or the method of sending a domain name system DNS request according to any one of claims 5 to 14 is executed, or the method of sending a domain name system DNS request according to claim 15 is executed, or the method of sending a domain name system DNS request according to any one of claims 16 to 19 is executed.